1. Field of the Invention
The present invention relates to a playpen and, more particularly, to a foldable playpen for placing a baby or child.
2. Description of the Related Art
A conventional playpen comprises a top frame and a bottom frame located under the top frame. The top frame includes four corner connectors, four foldable articulations mounted between the corner connectors respectively, and four side support rods each having an upper end mounted on a respective one of the corner connectors. Each of the four foldable articulations includes a mounting seat disposed between any two of the corner connectors, two pivot rods each having a first end pivotally connected with the mounting seat and a second end pivotally connected with a respective one of the corner connectors, and a folding device mounted on the mounting seat and releasably locked on each of the pivot rods to releasably lock each of the pivot rods onto the mounting seat. Thus, each of the foldable articulations can be expanded and folded by operation of the folding device so as to expand and fold the top frame. However, the mounting seat of each of the foldable articulations is supported by the pivot rods only, so that the top frame has a smaller strength. In addition, the mounting seat of each of the foldable articulations is not supported by the pivot rods solidly and stably, so that each of the foldable articulations of the top frame cannot be operated exactly and smoothly, thereby greatly causing inconvenience to a user when expanding and folding the top frame.